Steema Central

Posted: **Thu Oct 20, 2022 6:36 am**

: before alignment; before align.jpg (268.82 KiB) Viewed 4433 times

Hello,

I'm using a chart with a serie Line, and adding some marks on it, label style. I tried to locate the marks in "auto" but at the end, some marks is always over the line.
Is there any way to locate the marks on some area where there is no curve ?
See "LP2/3" and "HP5/6" marks below, they could be under the point, but I don't know how to do it.

:

The free component Microsoft Graph was doing this, with automatic callouts with well separated marks from the points if they were too close.

******** UPDATE 21st OCTOBER 2022 ***************

I finally succeded in finding a way to avoid overlapping between marks and lines.
Here is the code I used :

Code: Select all

 Private Sub modelgraph_afterdraw(sender As Object, e As Steema.TeeChart.Drawing.Graphics3DGdiPlus) Handles modelgraph.AfterDraw
        Dim series_index As Integer
        Dim mps As Steema.TeeChart.Styles.SeriesMarks.Position
        If modelgraph.Series.Count > 0 Then
            For Each s As Steema.TeeChart.Styles.Series In modelgraph.Series
                series_index = modelgraph.Series.IndexOf(modelgraph.Series.WithTitle(s.Title))
                    ' repositionning labels 
                    If s.Marks.Positions.Count > 0 Then
                        With s.Marks.Positions
                            For i As Integer = 0 To s.Count - 1
                                mps = s.Marks.Positions(i)
                                mps.Custom = True
                                Do While MarkOverlaps(i, s)
                                    With s.Marks.Positions(i)
                                        If s(i).Label Like "*1/2*" Or s(i).Label Like "*3/4*" Then
                                            .LeftTop.X = .LeftTop.X - 2
                                            .LeftTop.Y = .LeftTop.Y - 2
                                            .ArrowTo.X = .LeftTop.X + .Width / 2
                                            .ArrowTo.Y = .LeftTop.Y + .Height
                                        Else
                                            .LeftTop.X = .LeftTop.X + 2
                                            .LeftTop.Y = .LeftTop.Y + 2
                                            .ArrowTo.X = .LeftTop.X + 2
                                            .ArrowTo.Y = .LeftTop.Y + 2
                                        End If
                                    End With
                                Loop
                            Next i
                        End With
                End If
            Next
        End If
    End Sub

And the overlapping is detected like this :

Code: Select all

    Private Function MarkOverlaps(ValueIndex As Integer, s As Steema.TeeChart.Styles.Series) As Boolean
        Dim i As Integer

        Dim result1 As Boolean = False
        Dim result2 As Boolean = False

        With s.Marks.Positions
            For i = 0 To s.Count - 1
                If (i <> ValueIndex) Then
                    If s.Marks.Positions(i).Bounds.IntersectsWith(s.Marks.Positions(ValueIndex).Bounds) Then
                        result1 = True
                        Exit For
                    End If
                End If
            Next i

            If (ValueIndex = 0) Then
                    result2 = SegmentIntersectRectangle(s.Marks.Positions(ValueIndex).Bounds, s.CalcXPos(0), s.CalcYPos(0), s.CalcXPos(1), s.CalcYPos(1))
                ElseIf (ValueIndex = s.Count - 1) Then
                    result2 = SegmentIntersectRectangle(s.Marks.Positions(s.Count - 1).Bounds, s.CalcXPos(s.Count - 2), s.CalcYPos(s.Count - 2), s.CalcXPos(s.Count - 1), s.CalcYPos(s.Count - 1))
                Else
                    result2 = SegmentIntersectRectangle(s.Marks.Positions(ValueIndex).Bounds, s.CalcXPos(ValueIndex - 1), s.CalcYPos(ValueIndex - 1), s.CalcXPos(ValueIndex), s.CalcYPos(ValueIndex)) _
                    Or SegmentIntersectRectangle(s.Marks.Positions(ValueIndex).Bounds, s.CalcXPos(ValueIndex), s.CalcYPos(ValueIndex), s.CalcXPos(ValueIndex + 1), s.CalcYPos(ValueIndex + 1))
                End If

        End With
        Return (result1 Or result2)
    End Function

Now the problems I still have are the following :
- the repositionning works, but to see it i must click on the graph. It won't update the graph before I "touch it"
- after zooming on a specific area, the initial marks remain at their location, and are not displayed with the new view after zoom.
(attached 3 pictures, after alignment, after marks alignment, and after zoom)

I guess this is something very simple I miss, but I don't see....

Thanks

Posted: **Tue Oct 25, 2022 10:03 am**

Hello,

sorry for the delay—have you tried a call to tChart1.Draw() at the end of the AfterDraw event? If that doesn't work, could you post a project here I could run to have a look at what is happening?

Steema Central

marks over a line serie

marks over a line serie

Re: marks over a line serie